(CNN) - Hillary Clinton won the New Hampshire primary despite polls indicating she would lose by double-digit margins because three groups of Democratic voters cast their ballots for her.

Voters concerned about the economy, female voters, and union voters all voted for the New York Democrat by a considerably higher margin than expected.

The economy was the most important issue for Democrats, and Clinton bested Barack Obama by 9 percentage points on the issue. Clinton also did considerably better among women voters - nearly 60 percent of Democratic primary voters - beating Obama there by 13 percentage points. Female voters proved fatal to Clinton in Iowa – she lost among women there to Obama by 5 percentage points.

Finally, Clinton beat Obama among union voters by 10 percentage points. Union voters don’t play a major role in New Hampshire - only 20 percent of primary voters - but are considerably more of a factor in states down the road.